Phonetic printer of spoken words



March 29, 1955 M, v. KALFAIAN PHOIZIETIC PRINTER OF SPOKEN WQRDS 2Sheets-Sheet l Filed Dec. 3, 1952 I ONE CYCLE OF I I Fl/AIDANE/VTM.

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United States Patent PHONETIC PRINTER 0F SPOKEN WORDS Meguer V.Kalfaian, Los Angeles, Calif.

Application December 3, 1952, Serial No. 323,873

Claims. (Cl. 178-31) This invention relates to the analysis of speechwaves, and more particularly to those waves that are responsible for theintelligibility of phonetic characters in spoken sounds. Its main objectis to provide methods and means for the analysis and selection ofvarious frequency components that occur simultaneously duringpropagation of phonetic sounds, for the purpose of translating phoneticsounds into visible intelligible indicia. A corollary object is toprovide methods and means to translate those simultaneously selectedfrequency components into discrete signals for the actuation ofcharacter-printing keys, for example the keys of a modified electrictypewriter, or slotted code bars such as in teletypewriter devices, sothat spoken words may be translated into visual words. In the course oftranslating those simultaneous signals into singular discrete signals, anovel ratio meter is provided herein, which is capable of compensatingfor most all of the variables, such as, pitch, formants, etc., thatoccur in speech waves, due to different speakers voices. This ratiometer had been described in my Patent No. 2,613,273 issued October 7,1952; but it is particularly contemplated to be used in conjunction withthe system of speech wave analysis described in my copending applicationSerial No. 268,243 filed January 25, 1952, wherein, methods and meanshad been disclosed for shifting the variable frequency bands containedin speech waves to standard bands, whereby selection of phonetic soundscould be more accurately achieved for translating spoken sounds intovisible intelligible indicia.

In ordinary speech, each phonetic sound is produced in substantiallyreplica wave trains that repeat successively at a fundamental (pitch)frequency, during propa-; gation of the articulated sound. Thesuccession of these wave trains is effected by fairly regular puffs ofair from the glottis, which are set into vibration in the momentarilyformed resonant cavities of the vocal system. Each wave train containsall the phonetic information necessary, and its specific wave shape isformed by the.

number of frequency components that are produced in these cavities, andtheir relations with regard to frequency positions and relativeamplitude levels one with another. The basic frequency componentscomposing a pure phonetic sound are independent of characterizationcomponents, the latter of which are mainly produced by the larynx. Thecomposite structure of these latter.components is inconsistent in form,and it varies in a complex manner with the varying pitch of the speakersvoice. However, the frequency ratios of the basic components, and theirrelative amplitudes, remain substantially constant with respect to thefundamental frequency; even though the frequency locations of all thesecomponents may change in the entire spectrum band of the voice. Thus,the human intelligence interprets phonetic sounds by measuring theratios of basic frequency components, and their relative amplitudes,with respect to the fundamental frequency, without regard to thecharacterization components; the latter of which is interpreted as aform of voice quality.

To define characterization complexities, as an example, let one speakerpronounce certain phonetic sound (in natural voice) at first and secondfundamental frequencies. The listener can easily recognize thecharacteristic quality of the sound to be of the same speaker. But whenthe sound at the first fundamental is recorded and reproduced at thesecond fundamental (by speeding or retarding the movement ofreproduction), the

2,705,260 Patented Mar. 29, 1955 listener can easily detect the phoneticsound but cannot recognize the characteristic quality of the voice. Theconcept of this peculiar condition has been advanced by actualrecordings of male and female voices on magnetic tape. The consonantsounds had been both preceded and succeeded by vowel sounds, and thereproduction speed had been varied randomly. In all cases, the phoneticsound had been recognizable by a group of listeners.

A graphical comparison between the high pitched and low pitched voicesof the same phonetic sound, as shown in Fig. 1, indicates that the highpitched wave is purer in sound than the lower pitched wave. Moreoverthese two waves indicate that the characterization frequency componentsare mostly outside the regions of the basic bandwidth of the highpitched sound; these two conditions hold true in the average, fordifferent phonetic sounds (it is perhaps due to this peculiar conditionwhy the human intelligence can easily separate the characterizationcomponents from the basic components of phonetic sounds forrecognition). Thus, since the high pitched sound contains all the basiccomponents of phonetic information, it is possible to first transposethe frequency positions of all the components during propagation of thespeech waves, so that they will all be based on a single referencefundamental frequency, and set a boundary, within which to select thebasic frequency components for analysis. Thus it may be seen thatthrough the process of. frequency transposition, or standardization, andcharacterization-frequency filtration thereof, the true sounds ofphonetics may be derived from the original speech waves, for final andmore accurate analysis than by devices heretofore devised. In order tofurther advance the operational accuracy of phonetic selection, however,this invention contemplates to utilize the ratio meter, as described inmy above noted patent, in conjunction with the system of frequencytransposition, as described in my above noted 'co-pending application.When utilized in conjunction with the fre quency transposed speechwaves, the ratio meter will provide a large number of predeterminedadjustments, so that most of the undesired variables that still exist inthe frequency transposed waves will be reduced to negligible values forpractical purposes. The ratio meter will provide, by furthermodification, convenient output signals, representative of phoneticsounds, to operate printing mechanisms of different types, for example,the code bars such as used in teletypewriter devices.

In the drawings: Fig. 1 illustrates graph waveforms of speech waves;Fig. 2 is partly schematic and partly block diagram of the speech waveanalyzer in accordance with the invention; Fig. 3 is an amplitudecontrol device of the speech waves, as used in conjunction with thearrangement of Fig. 2; and Figures 4, 5, 6 are modifications of theratio meter utilized in conjunction with the arrangement of Fig. 2.

In Fig. 2, the original speech waves in block 1 are first frequencytransposed in block 2, and the various frequency components ofimportance are selected therefrom, by the band-pass filters, such as1111 to f4 inclusive. The oscillatory output waves of these pass bandcircuits are rectified, as shown, and further, the rectified outputs areindependently applied upon the electrostatic defleeting plates of acathode ray tube 3, which is utilized as the ratio meter. As describedin the foregoing, each phonetic sound is determined by the number offrequency components that are produced simultaneously, and theirrelations with regard to frequency positions and amplitude levels onewith another. Thus, in an exemplary embodiment of the invention,assuming that a certain phonetic sound had contained four simultaneousfrequency components, such as ft to f4, of various amplitudes, then theelectron beam 4 will be deflected angularly (from its normal centralposition), whose orientation is a function of the ratio of thedifferences of voltageamplitudes applied upon the four beam-deflectingplates. Accordingly, if a signal target 5 were placed in that path ofthe beam, as shown, a distinct output signal would be produced by thetarget, representative of the original phonetic sound. Similarly, othertarget sectors could be placed at predetermined positions, each ofwhich, when the beam strikes it, would produce an output signal,

water so as to render the technical application of water possible.Therefore, it is of no consequence which hydroxides or salts areemployed provided that they are sutliciently water-soluble and neutral,i. e. they must not form stable addition products with the nitrogencompounds to be separated and that they do not undergo reaction with thenitrogen compounds. Especially suitable salts are, for instance, commonsalt, sodium sulphate, sodium carbonate, sodium phosphate, sodiumacetate, sodium formate as well as the corresponding potassium salts andalkali hydroxides, such as sodium and potassium hydroxide. Furthersubstances which may be employed, are described, for instance, inBritish specification No. 475,818. The said salt solution may containaccording to the special requirements only small amounts of the salt orquantities up to saturation. On using alkali hydroxides, solutionscontaining from about to about 40% of the hydroxide are preferred.

Which of the nitrogen compounds is preferably absorbed depends on thenature of the absorbent applied. Thus, the invention permits of adaptingthe process to the prevailing conditions of the various absorbents inthe single steps of the reaction. On the other hand, it is possible toapply the absorbents in combination in the same step as far as theyagree as to their separating activity. For instance, the weak acids maybe employed in combination with neutral solvents boiling notsubstantially lower than the weak acid applied and being indiflierent tothe weak acid as well as to the nitrogen compounds and yieldinghomogeneous mixtures with the weak acid. Suitable solvents are forinstance o-dichlorobenzene, 1.2.4-trichlorobenzene, nitrobenzene,tetralin, dekalin, higher boiling aliphatic or aromatic hydrocarbons asfar as they are still liquid under the reaction conditions applied, aswell as higher boiling ethers, alcohols, ketones and polyalcohols.

The application of mixtures of the weak acids with the organic solventsis especially advantageous in the separation of ammonia from mixturescontaining methyl amines and in the separation of a mixture consistingof monoand dimethylamine. Furthermore, it is possible in the separationof trimethylamine from methylamine mixtures being free of ammonia toincrease the separating activity of the weak acids by addition of water.Of course, water must not be added in quantities exceeding saturation atthe temperatures employed.

The process according to the invention may be advantageously carried outby a continuous method by feeding the reaction mixture, if desired underpressure, in a reaction tower counter-currently to the flow of theabsorbent. By appropriately adjusting the flow velocity and thetemperature one or more nitrogen compounds are selectively dissolved inthe weak acids or in the said other absorbents applied whereas thenitrogen compounds not absorbed escape as vapours at the top of thereaction tower. The absorbed compounds are expelled from the absorbentas described above. By repeating the process once or several times eachof the components contained in the starting mixture may be obtained inpure form.

The process herein described is substantially different from thatdisclosed in German Patent 615,527. German Patent 615,527 comprises theseparation of trimethylamine and ammonia by treatment with acids inquantities insufiicient for neutralization. The resultant salts cannotbe decomposed again by merely heating or by reducing the pressure.

The invention is further illustrated by the following examples, withoutbeing restricted thereto.

Example 1 A mixture of 62.5% by volume of ammonia and 37.5% by volume oftrimethylamine is passed through a liquid mixture of by Weight of phenoland 75% by weight of o-dichlorobenzene. At the beginning the mixture iscompletely absorbed. After saturation of the absorbent a mixture of 90%by volume of ammonia and 10% by volume of trimethylamine escapes. Themixture of ammonia and trimethylamine dissolved in the absorbent isexpelled again by heating to 170 C. The mixture consists of 33% byvolume of ammonia and 67% by volume of trimethylamine. By repeating theprocess several times, each of the two components is obtained in pureform.

Example 2 A mixture of ammonia and dimethylamine is introduced into amolten mixture of aand fi-naphthol, the proportion of the mixtures being1:1. After saturation of the naphthol melt at about C. with the bases agas mixture consisting of 68% by volume of ammonia and 32% by volume ofdimethylamine escapes. By repeating the process several times, each ofthe two components is obtained in pure form.

Example 3 400 parts by weight of a solvent mixture consisting of 25% byweight of phenol and 75 by weight of o-dichlorobenzene is saturated witha mixture consisting of 78% by volume of trimethylamine and 22% byvolume of ammonia. 108 parts by weight of the mixture are totallyabsorbed. Thereupon pure trimethylamine is introduced into the saturatedsolution through a glass frit. The escaping gas mixture consists of 50%by volume each of ammonia and trimethylamine. As soon as the content ofammonia in the escaping gas decreases feeding of pure trimethylamine isstopped. By heating the solution 112 parts by weight of a 96.5%trimethylamine are obtained.

Example 4 M-cresol and a gas mixture of approximately equal parts byvolume of ammonia, dimethylamine, and trimethylamine are contacted incountercurrent in an ab sorption tower packed with Raschig rings, saidabsorption tower having a length of 2.50 m. and a diameter of 3 cm. 45liters of the aforesaid mixture and 120 grams of m-cresol are chargedeach hour. The gas escaping at the top of the tower consists of 99%ammonia whereas the mixture of methylarnines expelled from the absorbentis almost free from ammonia.

Example 5 The mixture of dimethylamine and trimethylamine set free onheating the sump obtained according to Example 4 is contacted withm-cresol in an absorption tower as indicated in Example 4. About 48liters of the mixture of the methylamines and 90 grams of m-cresol arecharged each hour. 98% trimethylamine escapes at the top of the reactiontower whereas a 90% dimethylamine is obtained by heating the sumpsolution.

Example 6 A mixture consisting of 55% by volume of ammonia, 15% byvolume each of mono-, di-, and trimethylamine is contacted incountercurrent with a technical cresol mixture (30 grams per hour) in anabsorption tower packed with Raschig rings, said absorption tower havinga diameter of 25 mm. and a height of 2.50 m.; the throughput of saidmixture amounts to 30 liters per hour. The nonabsorbed gas contains 100%of the amount of ammonia charged and of the trimethylamine charged andis free from monoand dimethylamine.

The mixture absorbed by the cresol and containing besides small amountsof trimethylamine, the whole monoand dimethylamine is contacted afterexpelling from the solvent with a mixture consisting of 1 part by weightof phenol and 3 parts by weight of o-dichlorobenzene in the samereaction tower and in similar manner.

monomethylamine escapes at the top of the reaction tower whereas 92%dimethylamine is obtained from the sump solution.

Example 7 A mixture of 49% by volume of ammonia and 17% by volume eachof mono-, di-, and trimethylamine at a rate of 29 liters per hour iscontacted, in countercurrent, at room temperature with a caustic sodasolution of 10% strength in an absorption tower packed with Raschigrings and having a height of 2.50 m. and a diameter of 25 mm. The gasmixture is fed at a point in the middle of the tower, the sump of theabsorption tower is heated to 45 C. When charging 70 cm. of caustic sodasolution per hour 100% trimethylamine is taken off from the top of thetower. The dissolved nitrogen compounds are practically free fromtrimethylamine.

The dissolved mixture of nitrogen compounds is expelled by heating andcontacted in a similarly constructed tower with a technical cresolmixture of such an amount that the monoand dimethylamine contained inthe mixture are dissolved whereas pure ammonia escapes at the top of thetower.

may also be achieved by different arrangements, as for example, byutilizing two opposing Windings in each relay, such as shown in theabove mentioned Patent No. 2,540,660, or in the arrangement given inPatent No. 2,556,975, June 12, 1951, the disclosure of which is herebymade part of this invention, as if fully included herein.

The monochrome photographic film 12 may also be arranged in colors, suchas shown in Fig. 5. In this case, the chromatic film 17 is interposedbetween a plurality of photocells 18, 19, 20, 21, etc., and the phosphorscreen 22 of cathode ray tube 23. In front of each photocell there isplaced a color filter, 24, 25, 26, 27, etc, each of which admits lightof a prearranged color to its associated photocell. Thus, when theelectron beam 28 luminesces the phosphor screen 22 at an area where thefilm 17 passes only red light, the photocell 18 becomes excited, whilethe others remain idle. These selected signals may then be applied upona phonetic prmter, for mechanical actuation.

For coding purposes, each section on the color film 17, representativeof a phonetic sound, may be arranged to have a color code, such as shownin the sect1onal drawing of the color film 17. In this drawing, threeprimary colors (red, green and blue) are shown, which collectivelyrepresent a prearranged phonetic sound. In order that the beam may coverall the primary colors in a given area, the dilferent colors may bearranged in thin stripes, as shown, so that the beam W111 always see allthe colors in that given section. In the case that 32 phoneticcharacters are utilized for final printing, only five different colors,and five photocells are needed. The outputs of these photocells are thenapplied upon the code bars, for example of a teletypewriter device, forfinal printing. For automatic volume control, the film may be arrangedwith a circular ring of another color, so as to efiect excitation of aphotocell, which may be used for controlling the amplitude level of thespeech waves.

The coding system just described, may also be adapted to the targetsectors of the ratio meter shown in Fig. 2. In such an arrangement, forexample, target sector may be divided into narrow strips, and theiroutput signals applied upon the code bars of a teleprinter. Because ofthe narrowness of the target strips, they may be physically arranged asshown in Fig. 6. In this arrangement, the target sectors 29 are mountedon an insulator base 30 (shown in cross sectional view), and on theother side of this insulator there are mounted electrical connectors 32,by way of metal pins 31. The electrical connectors are in the form ofmetal rings 33, 34, 35 and 36 (shown in front view), the outputs ofwhich are applied upon the code bars of a teleprinter. In one mode ofmanufacturing process, the connector rings may first be mounted on thesurface of the insulator base 30, with the said metal pins passingtherethrough, and the target strips mounted on the other side of theinsulator; touching the pins. For mounting the target strips, the wholesurface of the insulator may be coated with metal, and cut into sectionswith a die, or by photoetching method.

While I have described particular embodiments of my invention, numeroussubstitutions of parts, adaptations and modifications are possiblewithout departing from the spirit and scope thereof. To demonstrate onepossible modification of the arrangements given herein, it is possibleto utilize greater number of frequency selection from the total spectrumband of the voice frequencies, with lesser number of beam-deflectingmeans of the ratio meter, described herein, by sub-dividing and mixingthe outputs of the band-pass filters before applying upon thebeam-deflecting means of the ratio meter. This is possible due to themany prearrangements that may be made with the ratio meter. With suchoperating conditions, the frequency bands associated with some consonantsounds, for example, the sounds s, 2, which comprise bands of higherfrequencies than other sounds, may be separated from other sounds moreeasily than previously described.

What I claim is:

1. In speech wave analysis where each phonetic sound may be representedby substantially a specific combination of frequency components havingdefinite amplitude relations one with another, the system of derivingand reducing said combinations into singular discrete signalsrepresentative of said phonetic sounds, which comprises in combinationmeans for producing speech waves; means for sub-dividing said waves intoa plurality of predetermined frequency bands, and a plurality ofpass-band means therefor, for selecting same; means for rectifying theoutput oscillations of said pass-band means, whereby to obtain aplurality of substantially unidirectional signals, any collectivecombination of which representing a phonetic sound contained in thespeech waves; means for producing a ray; a plurality of ray-deflectingmeans arranged around said ray; means for individually applying saidplurality of simultaneous signals upon said plurality of deflectingmeans for deflecting the ray angularly from plurality of directions to amean angular position whose orientation is a function of the ratio ofdifferences of said plurality of angular deflections; a plurality oftarget sectors in the path of said ray, at predetermined directions fromthe undeflected path, each adapted to produce an output signal when theray strikes it, whereby indicating when the ratio of said differencescontrolling the deflection corresponds to the direction of that targetsector, so that each of said target sector will produce a singulardiscrete signal representing a combination of frequency componentsaforesaid.

2. The system as set forth in claim 1, wherein, each of said targetsectors is sub-divided into a plurality of narrow coded-sectors, sonarrow that the total number of coded-sectors comprising a code willintercept the stream of said ray simultaneously; and means for applyingthe outputs of said coded-sectors to code bars of a printing devicecomprising coded bars, thereby to effect translation of phonetic soundsinto visible intelligible indicia.

3. The system as set forth in claim 1 which includes a phonetic printer;and means for controlling the operation of the keys of said printer bysaid discrete signals, whereby to translate said phonetic sounds intovisible intelligible indicia.

4. Apparatus as set forth in claim 1, which includes anamplitude-control target disposed around the periphery of said pluralityof target sectors, in the path of said ray; means for deriving an outputsignal from the amplitude-control target whenever said ray strikes it;and means for applying last said signal upon the source of said speechwaves for controlling its output amplitude level, whereby the amplitudelevel of the speech wave may be automatically controlled to keep theangular deflection of said ray within the apparatus limits of saidplurality of target sectors.

The system as set forth in claim 1, which includes means for derivingoutput signals during transient periods of one phonetic sound to theother in the speech waves; and means utilizing last said signals forsuppressing the production of said discrete signals, thereby avoidingerroneous production of said discrete signals during said transientperiods.

References Cited in the file of this patent UNITED STATES PATENTS2,137,888 Fuller Nov. 22, 1938 2,195,081 Dudley Mar. 26, 1940 2,375,044Skellett May 1, 1945 2,575,909 Davis et al. Nov. 20, 1951 2,602,836Foster et a]. July 8, 1952 2,613,273 Kalfaian Oct. 7, 1952 2,646,465Davis et al. July 21, 1953

